Charged particle beam system and control method therefor

1. A charged particle beam system comprising:

a beam blanker for blanking a charged particle beam;

a sample stage on which a sample is tiltably held and thus can assume a tilt angle;

a blanking controller for controlling the blanking of the charged particle beam and causing a pulsed beam having a duty ratio to be directed at the sample; and

a tilt controller for controlling the tilt angle of the sample;

wherein the blanking controller sets the duty ratio of the pulsed beam based on the tilt angle of the sample.

2. A charged particle beam system as set forth in claim 1 , wherein said blanking controller sets said duty ratio in such a way as to increase with increasing absolute value of said tilt angle.

3. A charged particle beam system as set forth in claim 1 , wherein said beam blanker is made of electrostatic deflecting plates.

4. A control method for use in a charged particle beam system comprising a beam blanker for blanking a charged particle beam and a sample stage on which a sample can be tiltably held and thus can assume a tilt angle, said control method comprising:

irradiating the sample with a pulsed beam having a duty ratio while controlling the blanking of the charged particle beam; and

controlling the tilt angle of the sample;

wherein during the step of controlling the blanking, the duty ratio of the pulsed beam is set based on the tilt angle of the sample.